About 5.8 million American adults may no longer be prescribed drugs to treat high blood pressure under recently revised guidelines, according to a new study.

In February, the Eighth Joint National Committee released controversial guidelines that relaxed blood pressure goals in adults 60 and older from 140/90 to 150/90. The guidelines also eased blood pressure targets for adults with diabetes and kidney disease.

In this study, researchers used blood pressure data collected from more than 16,000 Americans between 2005 and 2010 to assess the impact of the revised guidelines.

The proportion of adults considered eligible for medication to treat high blood pressure would fall from about 41 percent to 32 percent, the authors concluded in the study published online March 29 in the Journal of the American Medical Association and presented Saturday at the American College of Cardiology annual meeting in Washington, D.C.

The researchers also said that 13.5 million adults -- most of them older than 60 -- who were considered to have poorly controlled blood pressure would now be viewed as having adequately managed blood pressure. That includes 5.8 million adults who would no longer require blood pressure pills.